XBOX use notification.

...ERRRRRRR. Not completely correct, as stated b4 I get real time notifications just the way I described. As for the rest of you *** *****, I was an ambassador also so get off ur high horse u pricks tryingto act like ur the only ones that know anything.
....

There is no need to attack others. Since you quoted me, let me tell you that no "high horsing" or acting pricky was intended.

As I described earlier, your method with the app works only if the kid decides to allow to show their online presence.

If the kid chooses to "appear offline", the app user won't get the real time notification.

Unless the original asker describes reasons why he needs real time usage information, there is no correct or wrong way to do things.

Since passcodes are mentioned:

If you want the notification for real-time alerts about your kid using the console is because you set a time limit (e.g. 1 hour of gaming per day), but you want your kid to only play after their homework is done at 4pm for example, you could go to the console
and sign in with your kid's account, and lock it with a passcode.

After 4pm, you send the kid a text message with the current passcode, so they can unlock their profile and play.

After one hour is up, and the kid has used up their "gaming allowance", you change the passcode to something different for tomorrow. Then the next day, after 4pm you send them a new text message with the updated code each day.

While you don't get information about when your kid uses the console, you can at least be sure they can't use it, until you give them permission to use it by sending them the current passcode for their account.

I am in agreement with WPAK statement to post on uservoice that is place where ideas are shared then voted upon and if enough then some do get implemented if it possible.

Hey fellas!

This is called the
Xbox passkey. The benefits and way to set up are posted on our website! Check it out and let us know if it helped!

I'm afraid, that due to privacy issues, such a function might not be implemented.

While you can keep track of your kid's console usage with the activity reports as XBF Javier R already suggested, all other "workarounds" like using the Xbox App and having your kid as a friend that notifies you when the kid goes online, can be avoided by
your kid when he chooses to "appear offline" in his profile settings.

Is there a certain reason WHY you need the real time information instead of the activity report? Maybe if you explained the situation and need for a real time notification, we might find a different solution?

Not 100% sure about this but i know that you can set a pass code to individual accounts that would/could prevent him from adjusting settings but not sure if appearing on/off line is affected by pass code or not but i think it will lock settings preventing
him from changing profile to appear offline. Like i said, I'm not 100% sure about that but it should work